Wat would make my heater and gas gauge not work in my 1989 cadilac divel

Without testing hard to say ! Your gas gauge not working could be the gauge it self is bad or the sending unit in the fuel tank is bad or somthing wrong with the BCM body computer . Are you talking about blower motor not working ? The blower motor is controlled by the BCM . Do you know how to do electronic testing ? I don't know if this year does it or not but on some cadillacs if you push the off and warmer button on the climate control panel the vehicle will show codes or will go into diagnostic mode . Been a few years , i worked at a Caddy dealer back then .You can look at free wiring diagrams at http://bbbind.com/free_tsb.html After you enter vehicle info . year ,make , model and engine size under system click on HVAC then under subsystem HVAC controls will automatically show ! Click the search button , then click on each blue link one at a time . You will see the complexity of your vehicle . Body computer , climate control panel . All electronic ! Fuel sending unit is a input to the BCM ,from there it goes to the fuel data center .

Disconnect neg / grnd battery cable. Replace Heater Blower Resistor. This will allow the heater blower to operate correctly

Go to fuse panel left of steering column. Ck to see if #17, 10A fuse, is blown.

Talking about fuel gauge issues and how do you how do you diagnose, ... is the dash unit right here, and obviously the gauge doesn't read correctly. ... to fix the fuel gauge, so you can actually fix the fuel gauge electronically by reflashing the program. ... How to Troubleshoot a Malibu Fuel Gauge & Dash Light Not Working ...Could be a bad fuse - fuse # 17 is a 15 amp fuse for the fuel gaugeCould be a bad float on the fuel gauge sending unit inside the gas tank ( it's with your electric fuel pump ) If the float gets a pinhole or crack in it , the float fills with gas and sinks so the gas guage reads empty all the time Could be a wiring problem

That is the way the festiva is designed. Heat only works on the defrost and the floor. Fresh and AC (if equipped) come through the vents.

If all your other gauges work, more than likely you have a bad sending unit in the gas tank or bad ground to the sending unit.

check your fues box were it say gagues

u will need to replace the fuel gauge sending unit.

I had same problem with my 89 cad. deville , I changed the BCM and since then no problems and everything works great now for over a year

Go to Autozone and purchase a Clymer repair manuel. It will show how to remove the dash. You need to find all the screws.